While I used to post a screenshot of the top 30 offensive and defensive gear sets with the Best Sets article, I have now provided a link to a zip file which contains the two spreadsheets I use for that, containing all of the hundreds of possible gear combinations. In order to work with it or understand them, I will provide here a short explanation of what each number represents, and how you should use it to compare gear.
With update 10.3, a new system of enhancing gear has been introduced, besides upgrading and enhancing, namely Embedding (Gems). So what does this feature exactly do and what do you need to do this? As in the article about upgrading and enhancing, I will try to combine everything you need to know into this one article. For a run down of what gears to embed with Gems, see this article.